The contact lens industry has undergone rapid advancements toward higher levels of visual correction. Manufacturers are progressing toward providing contact lenses that are designed to match a patient's refractive correction and fit. By moving beyond standard spherical lenses, manufacturers will be able to provide contact lens wearers with better visual acuity and overall comfort.
Metrology (measurement) techniques and instrumentation for evaluating lenses, however, have not kept up with the rapid advancement in lens technology. Current metrology, such as methods based on focimeters and moiré deflectometry, lacks the combination of spatial resolution, high sensitivity, and large dynamic range desired to accurately measure more advanced lenses. Current metrology techniques generally are limited to ophthalmic testing of the effective power of a lens and indirect measurements of power by translating a lens until collimation is detected.